HDR-using-only-Photoshop-layer-masks---featured-image

How to create HDR images using only Photoshop layer masks

Creating an HDR image is typically involved with a quite time-consuming workflow that consists of merging, tone-mapping and post-processing, possibly spanning several different software programs. But especially if you are creating a night HDR, there is a much simpler and quicker way of doing it, and your final image will also look more natural. In this excerpt from my video course Mask It Like a Pro! I will show you this technique that works by creating luminosity masks straight from the images themselves and using these masks to reveal only the well-exposed parts of your exposure series.

Video tutorial (excerpt from Mask It Like a Pro!)

Assumptions

I am assuming that you are starting with three exposures (e.g. a standard auto-bracketing series) and that these exposures are perfectly aligned.

Step 1: Load exposures as layers into Photoshop

All the source exposure need to be present as individual layers in a Photoshop document. If you are using Adobe Bridge to locate the files, this can be done as follows:

  1. Select all exposures in Adobe Bridge
  2. From the menu, choose Tools > Photoshop > Load Files into Photoshop Layers…

Note that the photos need to be aligned before you continue. So, if that’s not the case (e.g. you took them hand-held), select all layers, choose Edit > Auto-Align Layers… in Photoshop and then choose Auto as the Projection before you continue.

Also note that the exposures should be sorted according to their exposure value in the layer stack: The brightest exposure should be at the top and the darkest at the bottom

HDR-using-Photoshop-layer-masks-only---source-exposures

Locate the source exposures in Adobe Bridge (1) and load them as layers (2) into Photoshop (3).

Step 2: Create the first mask

To create a mask that hides the overexposed parts of the brightest exposure, do the following:

  1. Make sure that the brightest exposure is visible in the Layers palette.
  2. Switch to the Channels palette (Window > Channels).
  3. Hold down the ctrl key [win] / cmd key [mac] and click on the icon of the RGB channel (topmost channel). This will load the brightness information of the image as a selection.
  4. Switch back to the Layers palette, select the layer containing the brightest exposure and click the Add layer mask button at the bottom of the Layers palette.
  5. Select the new layer mask by clicking on the layer mask icon and press ctrl + I [win] / cmd + I [mac] to invert the mask.
HDR-using-Photoshop-layer-masks-only---Creating-first-mask

In the Channels palette, ctrl-click [win] / cmd-click [mac] on the top-most channel to load it as a selection (1). Then apply that selection as a layer mask to the brightest exposure (2),

The overexposed parts (e.g. on the bridge pillar in the foreground) will be hidden, while the nice blue sky will be preserved.

HDR-using-Photoshop-layer-masks-only---Close-up-mask

Detail view (2) of the mask (1). Note how all transitions are nicely captured from the original image.

Step 3: Create the second mask

The brightest parts of the scene are still overexposed after step 2. In order to blend in the darkest exposure (the one at the bottom of the layer stack) in exactly these places, we need to create another mask and apply it to the middle exposure. The procedure is very similar:

  1. Hide the top two layers so that only the darkest one is visible.
  2. Switch to the Channels palette again.
  3. Hold down the ctrl key [win] / cmd key [mac] and click on the icon of the RGB channel (topmost channel), just like you did in step 2. The difference is that the selection that will be loaded now contains the brightness information of the darkest exposure (the one that’s visible).
  4. Switch back to the Layers palette.
  5. Select the middle exposure and click the Add layer mask button at the bottom of the Layers palette. The selection you loaded will be applied to this layer in order to hide its overexposed parts and let the darkest exposure shine through in those places.
  6. Select the new layer mask by clicking on the layer mask icon and press ctrl + I [win] / cmd + I [mac] to invert the mask.
HDR-using-Photoshop-layer-masks-only---Second-mask

View of the second mask. It hides only the brightest pixels.

HDR-using-Photoshop-layer-masks-only---Final-masks

Final layer stack (1) with the masks applied to the top two exposures and the final blended image (2).

Step 4: Adding some adjustments (not shown in the video)

The resulting image has all the details from the three exposures, but it may look a bit dull due to the tonal compression. In order to change that, you can add some adjustments. Note that in order to constrain these adjustments, you can use the same masks that are applied to the image layers.

  1.  Reload the selection from the first mask we created by holding down the ctrl key [win] / cmd key [mac] and clicking on the layer mask icon.
  2. Open the Adjustments panel (Window > Adjustments) and create a new Curves layer. The new adjustment layer will automatically get a layer mask created from the active selection.
  3. Adjust the contrast as you wish to work on the darkest parts of the image.

Repeat this procedure and press shift + ctrl + I [win] / shift + cmd + I [mac] to invert the active selection before you add the next Curves layer. This will create a Curves adjustment that only takes effect on the brightest parts.

Final tips

This technique works best for images with a large contrast. Night HDR shots are perfectly suited. For scenes with a more even distribution of tones, there is too much overlap between the masks so that you need to tweak them in most cases to make this work.

But I encourage you to experiment with this technique to find out if is fits your style of shooting. Remember, if you want to practice with the original source images, feel free to download the Pics-to-play-with archive. It’s free, it’s fun, and it takes the guess work out of the equation.

Finally, if you want to learn everything about layer masking, check out my 6-hour video course Mask It Like a Pro! It comes with 21 lessons and a ton of resources for you to practice – all tightly integrated in a convenient learning environment.

Mask It Like a Pro!

The complete guide to layer masking
in Photoshop CS5 / CS6 & CC

6-hour video course
21 lessons
20+ resources

Have fun!

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5 Comments on "How to create HDR images using only Photoshop layer masks"


Guest
Neil Hobbs
2 years 7 months ago

great little tutorial, have downloaded your images to experiment and it works very well. You have managed to explain this “black magic” so I can understand it, many thanks

Guest
Andrew
2 years 4 months ago

Nice tutorial thanks!

Would you be open to doing these to a number of photographs ive taken ?

Guest
5 months 16 days ago

Are all of your tutorials CLOSED CAPTIONED? I cannot find that information anywhere on the website. Thank you.